10 Riveting Facts About Mars

Mars's dust storms can be global. In these images taken a month apart in 2001, the dust storm near the southern polar ice cap (left) soon enveloped the entire planet (right).
Mars's dust storms can be global. In these images taken a month apart in 2001, the dust storm near the southern polar ice cap (left) soon enveloped the entire planet (right).
NASA/JPL-CALTECH/MSSS

Few celestial objects have fascinated humankind throughout history more than the Red Planet. For over a century, we've longed to know more about Mars and the beings that we speculated lived there. When NASA dispelled the notion of creatures scurrying along the rusty plains, it raised a more tantalizing prospect: that we might one day be the creatures that call Mars home.

Mental Floss spoke to Kirby Runyon, a researcher at the Johns Hopkins University Applied Physics Laboratory, and Tanya Harrison, the director of research for Arizona State University's NewSpace Initiative, to learn more about the place your kids might live one day.

1. A MARTIAN YEAR LASTS JUST UNDER TWO EARTH YEARS.

It takes 687 Earth days for the Red Planet make its way around the Sun. A Mars day—called a sol—lasts 24.6 hours, which would be a nuisance for the circadian rhythms of astronauts (but not as bad as a day on Venus, which lasts 5832 hours).

2. IT'S NOT AS HOT AS IT MIGHT LOOK.

Mars looks desert-hot—New Mexico with hazy skies, red because of its iron oxide soil—but is actually very cold, with a blistering hot sol being 70°F, and a cold sol a brisk -225°F. Its dust storms can be huge; in 2018, one storm grew so large that it encompassed the entire planet for more than a month. (You can see a similarly huge dust storm in the image above.)

3. MARS IS MUCH SMALLER THAN EARTH ...

Compared to Earth, Mars is a tiny Styrofoam ball, with a diameter just over half of ours and one-tenth of our mass. Its gravity will be an absolute nightmare for future colonists, at .38 that of their native planet. (That means a person weighing 100 pounds here would weigh just 38 pounds on Mars.)

4. ... AND ITS ATMOSPHERE IS MOSTLY CARBON DIOXIDE.

You won't want to get a breath of fresh air on Mars unless you're trying to suffocate: Its atmosphere is 95.32 percent carbon dioxide, with a little nitrogen and argon thrown in. (Earth's atmosphere, by contrast, is mostly nitrogen and oxygen.) When you do try to take that single, hopeless breath, the tears on your eyeballs, saliva in your mouth, and water in your lungs will immediately evaporate. You won't die right away, but you'll probably want to.

5. IT HAS TWO MOONS, BOTH WITH BETTER NAMES THAN OURS.

They're called Phobos and Deimos, which translate to Fear and Dread, respectively. They're shaped like potatoes and don't exactly fill the evening sky: Standing on the Martian surface, Phobos would appear to be about one-third the size of Earth's moon; Deimos would look like a bright star.

Future human Martians will have to enjoy Phobos while they can. The tidal forces of Mars are tearing Phobos apart; in 50 million years, the big potato will disintegrate.

In the meantime, Phobos is one of the stepping stones NASA plans to take on its journey to Mars. No part of human exploration of the Red Planet is easy, and before we land on Mars (and then have to figure out how to launch back into space and somehow get back to Earth), it's vastly easier to land on Phobos, do a little reconnaissance, and then take off and return home. As a bonus, on the journey to Phobos [PDF], astronauts can bring along hardware necessary for eventual Martian settlement, making the ride a lot easier for the next astronauts.

6. MARS IS HOME TO THE TALLEST MOUNTAIN IN THE SOLAR SYSTEM.

The tallest mountain on Earth, Mount Everest, is 29,029 feet tall. Olympus Mons on Mars is over 72,000 feet in height, making it the tallest mountain by far on any planet in the solar system.

Olympus Mons isn't the only extraordinary Mars feature: Mountaineers might also want to check out NASA's trail map for hiking the famous Face on Mars. If canyons are more your speed, you'll want to visit Valles Marineris. It is the size of North America and, at its bottom, four miles deep. (In the solar system, only Earth's Atlantic Ocean is deeper.) Once Earth's ice caps finish melting, you can always visit the ones on Mars. (If you have a telescope, you can easily see them; they are the planet's most distinctive features visible from your backyard.)

7. THE IDEA OF MARTIANS GOES BACK OVER A CENTURY.

That's partially because of popular fiction (War of the Worlds, the 1897 novel by H.G. Wells, sees a Martian invasion force invade England) and partially because of Percival Lowell, the famed astronomer who wrote prolifically on the canals he thought he was observing through his telescope, and why they might be necessary for the survival of the Martian people. (Mars was drying up.)

Though it's easy to dismiss such conclusions today, at the time Lowell not only popularized space science like few others, but left behind the Lowell Observatory in Flagstaff, Arizona—one of the oldest observatories in America and the place where Clyde Tombaugh discovered Pluto.

8. IF THERE ARE MARTIANS, THEY ARE MICROBES.

Today, scientists work tirelessly to unlock the complex geologic history of Mars, to determine whether life exists there today, or did long ago. "We think that Mars was most globally conducive to life around 3.5 to 3.8 billion years ago," Runyon tells Mental Floss. "In the Mars geologic history, that's the end of the Noachian and toward the beginning of the Hesperian epochs." There may once have been a hemispheric ocean on Mars. Later, the world might have alternated between being wet and dry, with an ocean giving way to massive crater lakes. Where there's water, there's a good chance of life.

"If we found life on Mars—either extinct or current—that's really interesting," says Runyon, "but more interesting than that, is whether this life arose independently on Mars, separate from Earth." It is conceivable that meteorite impacts on Earth blasted life-bearing rocks into space and eventually to the Martian surface: "A second life emergence on Mars is not just a geological question. It's a biogeochemical question. We know that Mars is habitable, but we haven't answered the question of whether it had, or has, life."

9. NASA SPENDS A LOT OF TIME OUT THERE.

Mars hasn't hurt for missions in recent years, though scientists now warn of an exploration desert beyond 2020. But that doesn't mean we humans don't have eyes on the planet. Presently in orbit around the planet are the Mars Reconnaissance Orbiter, which images and scans the planet; MAVEN, which studies its atmosphere; Mars Express, the European Space Agency's first Mars mission; MOM, the first Mars mission by the Indian Space Research Organization; the ESA's ExoMars Trace Gas Orbiter, which is searching for methane in the Martian atmosphere; and Odyssey, which studies Mars for water and ice signatures, and acts as a communications relay for vehicles on the ground.

Rolling around on the Martian surface are Curiosity and Opportunity—NASA missions both—which study Martian geology. Though the Russians and Europeans have tried mightily to do so, NASA is the only space agency to successfully land spacecraft on the Martian surface (seven times).

In November 2018, the InSight mission will land on Mars, where it will study the planet's interior. In 2020, NASA will land the Mars 2020 rover; where Curiosity studies Mars for signs of habitability, Mars 2020 will look for inhabitants.

"It is going to collect samples that will hopefully be brought back to Earth," says Runyon. "The three landing sites selected for Mars 2020 are Northeast Syrtis, Jezero Crater, and Columbia Hills within Gusev Crater, which is where the dead rover Spirit is currently sitting. Each of these sites is a hydrothermal environment dating from the Noachian-Hesperian boundary. These are some of the most perfect places to look for past signs of Martian life, and can help answer the question of whether life had a second genesis on Mars."

10. MARS IS CHANGING, BUT NOBODY KNOWS WHY.

"Most people don't realize how active Mars is," Harrison tells Mental Floss. "Other planets aren't just these dead worlds that are frozen in time outside of our own. There are actually things happening there right now." Imagery from the HiRISE and Context Camera instruments on the Mars Reconnaissance Orbiter have revealed such events as avalanches, sand dune erosion [PDF], and recurring slope lineae (flowing Martian saltwater).

Things are moving, but it's not always clear why. "There's a lot of material that has been eroded away," says Harrison. "We have entire provinces of the planet that look like they've been completely buried and then exhumed. And that's a lot of material. The big question is, where did it all go? And what process eroded it all away?" Curiosity might help answer the question, but to really understand the processes and history of the fourth rock from the Sun, we're going to need to send geologists in spacesuits. "You can't replace human intuition with a rover," Harrison says. "Looking at a picture on your computer is not the same as standing there and looking around at the context, stratigraphic columns, being able to pick up the rocks and manipulate them, take a hammer to things. So once humans land on the surface, it'll be kind of like the difference between what we knew about Mars from Viking and Mars Global Surveyor and then the revolution between Mars Global Surveyor and Mars Reconnaissance Orbiter. Our view of what we think happened on Mars is going to completely change, and we'll find out that a lot of what we thought we knew was wrong."

A version of this story ran in 2017.

14 Retro Gifts for Millennials

Ravi Palwe, Unsplash
Ravi Palwe, Unsplash

Millennials were born between 1981 and 1996, which means the pop culture they grew up with is officially retro. No matter what generation you belong to, consider these gifts when shopping for the Millennials in your life this holiday season.

1. Reptar Funko Pop!; $29

Amazon

This vinyl Reptar figurine from Funko is as cool as anything you’d find in the rugrats’ toy box. The monster dinosaur has been redesigned in classic Pop! style, making it a perfect desk or shelf accessory for the grown-up Nickelodeon fan. It also glows in the dark, which should appeal to anyone’s inner child.

Buy it: Amazon

2. Dragon Ball Z Slippers; $20

Hot Topic

You don’t need to change out of your pajamas to feel like a Super Saiyan. These slippers are emblazoned with the same kanji Goku wears on his gi in Dragon Ball Z: one for training under King Kai and one for training with Master Roshi. And with a soft sherpa lining, the footwear feels as good as it looks.

Buy it: Hot Topic

3. The Pokémon Cookbook; $15

Hop Topic

What do you eat after a long day of training and catching Pokémon? Any dish in The Pokémon Cookbook is a great option. This book features more than 35 recipes inspired by creatures from the Pokémon franchise, including Poké Ball sushi rolls and mashed Meowth potatoes.

Buy it: Hot Topic

4. Lisa Frank Activity Book; $5

Urban Outfitters

Millennials will never be too old for Lisa Frank, especially when the artist’s playful designs come in a relaxing activity book. Watercolor brings the rainbow characters in this collection to life. Just gather some painting supplies and put on a podcast for a relaxing, nostalgia-fueled afternoon.

Buy it: Urban Outfitters

5. Shoebox Tape Recorder with USB; $28

Amazon

The days of recording mix tapes don’t have to be over. This device looks and functions just like tape recorders from the pre-smartphone era. And with a USB port as well as a line-in jack and built-in mic, users can easily import their digital music collection onto retro cassette tapes.

Buy it: Amazon

6. Days of the Week Scrunchie Set; $12

Urban Outfitters

Millennials can be upset that a trend from their youth is old enough to be cool again, or they can embrace it. This scrunchie set is for anyone happy to see the return of the hair accessory. The soft knit ponytail holders come in a set of five—one for each day of the school (or work) week.

Buy it: Urban Outfitters

7. D&D Graphic T-shirt; $38-$48

80s Tees

The perfect gift for the Dungeon Master in your life, this graphic tee is modeled after the cover of the classic Dungeons & Dragons rule book. It’s available in sizes small through 3XL.

Buy it: 80s Tees

8. Chuck E. Cheese T-shirt; $36-$58

80s Tees

Few Millennials survived childhood without experiencing at least one birthday party at Chuck E. Cheese. This retro T-shirt sports the brand’s original name: Chuck E. Cheese’s Pizza Time Theatre. It may be the next-best gift for a Chuck E. Cheese fan behind a decommissioned animatronic.

Buy it: 80s Tees

9. The Nightmare Before Christmas Picnic Blanket Bag; $40

Shop Disney

Fans of Tim Burton’s The Nightmare Before Christmas will recognize the iconic scene on the front of this messenger bag. Unfold it and the bag becomes a blanket fit for a moonlit picnic among the pumpkins. The bottom side is waterproof and the top layer is made of soft fleece.

Buy it: Shop Disney

10. Toy Story Alien Socks; $15

Shop Disney

You don’t need to be skilled at the claw machine to take home a pair of these socks. Decorated with the aliens from Toy Story, they’re made from soft-knit fabric and are big enough to fit adult feet.

Buy it: Shop Disney

11. Goosebumps Board Game; $24

Amazon

Fans that read every book in R.L. Stine’s series growing up can now play the Goosebumps board game. In this game, based on the Goosebumps movie, players take on the role of their favorite monster from the series and race to the typewriter at the end of the trail of manuscripts.

Buy it: Amazon

12. Tamagotchi Mini; $19

Amazon

If you know someone who killed their Tamagotchi in the '90s, give them another chance to show off their digital pet-care skills. This Tamagotchi is a smaller, simplified version of the original game. It doubles as a keychain, so owners have no excuse to forget to feed their pet.

Buy it: Amazon

13. SNES Classic; $275

Amazon

The SNES Classic is much easier to find now than when it first came out, and it's still just as entertaining for retro video game fans. This mini console comes preloaded with 21 Nintendo games, including Super Mario Kart and Street Fighter II.

Buy it: Amazon

14. Planters Cheez Balls; $24

Amazon

Planters revived its Cheez Balls in 2018 after pulling them from shelves nearly a decade earlier. To Millennials unaware of that fact, this gift could be their dream come true. The throwback snack even comes in the classic canister fans remember.

Buy it: Amazon

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Uranus Reaches Opposition on Halloween in 2020

Christine Schmitt, Flickr // CC BY-NC-ND 2.0
Christine Schmitt, Flickr // CC BY-NC-ND 2.0

Uranus is roughly 1.75 billion miles away from Earth, which makes it difficult to spot without a telescope most nights. But on Saturday, October 31, the seventh planet from the sun will be worth looking for. Uranus reaches opposition that night, making it appear extra bright in the night sky.

What Is Uranus at Opposition?

An opposition occurs when the Earth falls perfectly between another planet and the sun. When this happens, the sun's light appears to fully illuminate the planet's surface, boosting its brightness level to the maximum.

Uranus reaches opposition on October 31 in 2020. During this event, Uranus will hit a limiting magnitude of 5.86, which is about the minimum brightness for what's visible with the naked eye.

How to Look for Uranus at Opposition

Spotting Uranus at opposition will be slightly more difficult in 2020 than in years past. The phenomenon coincides with a full moon that will make dimmer stars and planets—including Uranus—harder to see in the night sky. The planet sits in the constellation Aries, which regrettably appears close to the moon for most of the night.

Uranus should appear as a small, blue-green disc when using a telescope. Even if you have trouble spotting the seventh planet, it will still be worth checking out the night sky on October 31: Halloween this year coincides with a rare blue moon.